VMware LUNs

afnsatntapp1.afni.net Data ONTAP Release 7.2.6.1 /vol/VMFS3 is full (using or reserving 100% of space and 0% of inodes, using 100% of reserve).

Here is the scenario of the LUN. It is a 251 GB Flex volume with a 250 GB LUN used for VMware. We are not using snapshots either. Also, what are the best practices for creating Volumes that will be used for VMware LUNs?